Summer bass are scattered, true. And yes, as the water temperature rises toward the 80's hot weather fishing can get tough, but not for the reasons you might think. The bass are still there and if you can find them you can catch them. Some bass will remain shallow or very close to shallow water, others retreat to deeper water structure.
Where you'll likely find summer bass.
"He Who Speaks The Truth Stabs Falsehood In The Heart"
I'd venture a quess that many of us believe the following about largemouth bass and why hot weather fishing is so tough as to even be avoided.
First of all, largemouth bass don't stop feeding when it's hot. They feed continuously and they feed well. The difficulty anglers have catching bass when hot weather fishing, the so called "dog days of summer", is not a consequence of largemouth not feeding. It's due to their inability to find them and even if found, to present, properly, the most effective lures.
Bass function very well at temperatures between 55° and 85°. The water temperature at which a bass most efficiently digests its food is between 75° and 85°. Obviously bass are in a comfort zone in what we might consider "warm" or even "hot" water.
Think about that. Clearly there is a wide range of temperature and habitat within which largemouth can live, which includes feeding. Not doing so is not in the cards for summer bass. Where they choose to reside and feed is the real "summer puzzle" the angler must solve when hot weather fishing.
Secondly, all bass do not, in fact, move to deep water for the summer. Especially with natural lakes where there is ample aquatic vegetation. The popular notion that they do so to avoid the summer heat is simply untrue. Quite simply largemouth bass like heat. At least until it reaches the area of 97° or 98° where it can be fatal. And remember, deep is always relative to the structural characteristics of a given body of water.
The body temperature of a largemouth bass in summer is "up" like that of the water. So too is its metabolism which in turn causes increased energy levels and active feeding to match or exceed its racing metabolism. In summer, the bass enjoys high energy which supports fast, powerful swimming needed to catch prey. Now is the time to eat!!!!!
If food is shallow, that is where some summer bass will be. Look for them in and around aquatic grasses, coontails, lily pads and duckweed as that will be where there is shade (to hide in for ambush, not necessarily to avoid the sun) and/or a higher level of oxygen saturation. They will primarily be there because that's where the crawfish, frogs, baitfish and bluegill will also be. They can also be found under docks, stumps and laydowns.
If the largemouth's primary food source are baitfish like gizzard shad or threadfin shad, they may very well venture into deeper water to feed. This is a common pattern in man made reservoirs where aquatic plants are scarce. The preferred water temperature of most baitfish is much cooler than that of their nemesis, "old bucketmouth". So if the latter wants to eat them he/she will find it necessary to forgo the "perfect temperature" and pursue this prey into deeper water.
Lastly, a largemouth will indeed seek out that magic "preferred temperature" range of 86° to 89°, where all is good and their metabolism functions most efficiently. Often it is found in shallow water. However, even though temperature may be just right, the oxygen saturation level and/or availability of food may not be. Thus,largemouth bass must often leave the comfort of home to feed or find more thoroughly oxygenated water which may in fact be cooler than the "perfect" water temperature they desire.
In many respects they're like us. We humans are most comfortable when the air around us is between 72° and 77°. It would be great if we could find this temperature and stay there, never to leave. Why should we? It's perfect. Wait a minute though. What if we get hungry or our loyal dog resting by our side passes the mother of all gas? In both cases, we find it beneficial to leave our thermal comfort zone and travel to another to satisfy other needs. So it is with the largemouth bass as well.
Words To Remember For Summer Bass
Shallow Summer Bass
Once spawned out largemouth scatter. In lakes that contain an abundance of vegetation, usually natural lakes, bass move to it and take up temporary residence. The grass they choose might be shallow (2-5') if the water is stained or a bit deeper (5-15') if the lake water is clear. Offshore grass that extends outward from the shoreline into deeper water probably offers bass the most favorable conditions. Here they find shade for hiding in ambush and an abundance of prey on which to feed.
Specifically when and where do you fish once you find "bass in the grass"?
Structure Lakes and Shallow Bass Hangouts
These are lakes that most consider to be in the category of man-made reservoirs and which have as a rule less grass than natural lakes. Edges and ledges play an important role in largemouth location in these lakes. Look for old river or creek channels and roadbeds that run out from the larger coves and creeks toward to the main channel.
These are avenues along which largemouth bass will migrate from from the spawning beds to deeper water. Remember, this migration does not happen in a day. It takes place over weeks. The bass will move along these routes stopping several places temporarily before ultimately reaching structure in deeper water where they spend most of their time during high summer.
The cover and structure, especially if it's isolated, such as stumps, laydowns, bush, rock piles and ledges along these "shallow" routes is where they "hold" for a while. Find them and it's a feast. Miss them or use an incorrect presentation after finding them and it will be famine.
Remember too that even after reaching their deep water destination, largemouth bass will make daily feeding runs back to shallow water along these very same routes. In reservoirs, the cover and structure I've referenced may be found along these routes in water five to twenty feet deep, which in a highland reservoir is likely shallow compared to the rest of the lake.
What About Current?
In reservoirs intermittent moving water, current, is a fact of life. Water is "drawn down" for a variety of reasons but the important one for bass anglers is the effect of that draw down on bass. Basically, it wakes everybody up!
Current is a stimulating factor to both baitfish and bass alike. Current stirs up water as it flows past and swirls around points. This brings oxygenated water, nutrients and prey fish together closer to the surface and of course right behind them are the bass.
Largemouth will hold behind cover facing upstream and wait in ambush for passing prey. Or, since prey fish tend to school when current is present, they will aggressively pursue these bait balls.
Deep Summer Bass
After spawn many summer bass, at least those in lakes that do not have sufficient cover in the form of grass and the abundance of food that goes with it, choose to move out on off shore structure to spend the entire summer on the main lake. Summer bass in these structure lakes follow the creek channels, roadbeds and channel ledges from their spawning coves to the main channel. Here they will relate to structure the majority of the time as cover is sparse. The type structures upon which they take up residence can be points, channel drop offs, old roadbeds, timber lines, humps, saddles and bluff walls close to the main channel.
This is a summer bass pattern that offers anglers a chance to have one of those 30 fish days we always hear about. Why? Because the largemouth tend to "school" on deep structure, especially points and humps. Find them and you will likely find a bunch!